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World Population. Ch. 4 Sec. 1. Demography. The study of population #’s Ethnicities Common characteristics Distribution/ Density. Demography. The study of human populations, including their size, growth, density, distribution, and rates of births, marriages, and deaths.
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World Population Ch. 4 Sec. 1
Demography The study of population • #’s • Ethnicities • Common characteristics • Distribution/ Density
Demography • The study of human populations, including their size, growth, density, distribution, and rates of births, marriages, and deaths.
According to the United Nations, the World reached 6 billion people on October 12, 1999.
According to the United Nations, the World reached 7 billion people on October 31, 2011.
Population Growth • 1000-1800: 1 billion ppl • 1800-1950: 2 billion ppl • Doubled in 150 yrs • 1950-2000: 6 billion ppl • Tripled in 50 years • By 2050: 9 billion ppl!!
Between 1800 and 1950, the world population doubled, reaching 1 billion. We reached 6 billion in 1999. At its current rate, we will pass 9 billion by the year 2050.7 Billion Vid
Growth Rates • Death rate: # of ppl that die every year per 1,000 • Birth rate: # of ppl born every year per 1,000 • Natural Increase (growth rate)= BR – DR
Growth Rates • Life expectancy- average number of years ppl live w/ in a given population • Fertility rate- (avg. amount of children/family) • Infant mortality rate- # of deaths of infants under 1 yr. per 1,000 live births • Child mortality rate- # of deaths of children ages 1-5 per 1,000
Fertility Rates 2.1 is generally regarded as a replacement rate (the rate at which a population neither grows nor shrinks) in the developed world. In less developed countries this rate should be higher (2.8?). Iran 4.7 Mexico 2.57 USA 2.0 Haiti 4.3 Italy 1.2 India 3.0 Russia 1.3 China 1.82 Why do women choose to have so many children in some countries and not it others?
Fertility Rates 2.1 is generally regarded as a replacement rate (the rate at which a population neither grows nor shrinks) in the developed world. In less developed countries this rate should be higher (2.8?). Iran 4.7 Mexico 2.57 USA 2.0 Haiti 4.3 Italy 1.2 India 3.0 Russia 1.3 China 1.82 Why do women choose to have so many children in some countries and not it others? • High infant mortality • No Social Security • Cultural preferences and fashion
Doubling time: • # of yrs. it takes a pop. to double in size • Parts of Asia, Africa, Latin Am. = 25 yrs. • Wealthy countries = 300 yrs.
Growth Rates • How would death rates ? • Better health care/ meds. • More food • Better technology • Better living conditions, sanitation (think after Industrial Revolution)
Growth Rates • Zero Population growth occurs when BR = DR • Usually happens only in wealthy countries • Most rural areas have tradition of many kids (farm work)
90% of earth's population growth occurs in less developed countries.
Population Problems • What would be problems of rapid growth? • Enough food to feed all • Resource shortages (water, housing, clothing) • Age distribution (too young)
Population Positives • What are good things that come with growth? • Levels of technology/creativity rises • Adv. in agriculture help food prod. • Enough workers to keep economy going
Negative Pop. Growth • Occurs when DR > BR • Not enough workers • Labor must be brought in problems b/w different cultures
Population Distribution • Pop. Dist. = pattern of human settlement • Due to inhospitable land, ppl only live on 1/3 of Earth’s land • Ecumene= portion of earth occupied by permanent human settlement • Need 3 things: • Available water, fertile soil, & a good climate
Which continents are the most densely populated? What regions tend to be the least populated- think climate? Which is more populated- urban areas or rural areas?
Population Density • Pop. Dens.= ppl per sq. mile • Total population / total land area (arithmetic pop. dens.) • Some countries have wide open areas= low pop. dens. • Some are tinier countries= high pop. dens. • Ex: Belgium & Niger
Population Density • Uneven distribution- not all land is usable • Egypt: 99% of pop. lives w/in 20 miles of Nile the rest is desert • Use physiological pop. dens. = • Total population / total arable land • 181 ppl/sq. mile vs. 5,807 ppl/sq. mile
Population Movement • Migration: ppl move place to place • City to city, suburb to suburb, rural to urban
Urbanization • What are reasons to move to the city? • Jobs • Education • Land goes bad • Health care/ social services ½ of world’s population lives in cities!
Migration • Between countries: • Emigrants in home country • Immigrants in new country • Reasons to leave: • War, food shortages, jobs, education, oppression/ persecution, disaster